1. Field of the Invention
The invention relates to a glazed element having a high insulating power provided with a plastic profile, especially intended to be fastened to a bearing structure.
It relates more particularly to the fastening of a glazed element having a high insulating power to a bearing structure by means of a technique consisting of fastening the glazed elements via its perimeter using a peripheral plastic frame.
2. Discussion of the Background
The description will be given with reference to the process for depositing a peripheral plastic frame using the techniques of deposition by injection molding, but the invention is not limited to this type of deposition.
In general, the glazed elements thus fastened are monolithic glazing assemblies or laminated glazing assemblies. In fact, such glazing assemblies, because of their structure and their mechanical behavior, may easily be provided with profiles around their periphery. The usual techniques of depositing a plastic profile on monolithic or laminated glazing assemblies by injection molding have been extensively described in many documents. These techniques form the subject of a great deal of research and of many improvements. At the present time, they are well controlled and widely used. However, these types of glazing assemblies do not meet the criteria of acoustic and thermal comfort which are desired in recent constructions.
In order to achieve thermal and/or acoustic insulation, it is usual to produce insulating glazing assemblies consisting of two substrates separated from each other by a relatively large air cavity, the sealing of which is provided in a known manner by a peripheral seal, and are supported by a frame which will be called hereinafter the supporting frame.
Each of the substrates may be a single plate of glass or may have a laminated structure. However, it should be noted that the usual techniques for depositing a peripheral plastic frame cause certain problems. This is because such insulating glazing assemblies have not been designed to withstand high peripheral pressures, because of the nature of the peripheral seals. The application of high pressures such as, for example, those necessary in the thermoplastic injection molding technique, would cause the peripheral seal to be crushed and, as a consequence, would therefore cause peripheral deformation of the glass sheets making up the insulating glazing panel. This deformation embrittling the insulating glazing panel and possibly even causing it to shatter.
Techniques for depositing a peripheral frame on insulating glazing assemblies are known. European patent EP-B-236,211 describes a glazing assembly consisting of two glass sheets separated by a dehydrated air cavity. The peripheral seal is obtained by in situ reactive injection molding under high pressure. A device which includes traction means has been proposed for producing this glazing assembly. These means pressing each glass sheet of the glazing assembly against a wall of the mold during the molding operation. In this way, the peripheral seal is prevented from being crushed.
It is, therefore, necessary to adapt the usual deposition techniques when these are applied to insulating glazing assemblies, thereby, considerably, increasing the cost of the glazing assembly.
Moreover, the usual insulating glazing assemblies provide a level of thermal insulation which is deemed to be unsatisfactory for some applications. In order to remedy this, it is known to produce glazing assemblies which comprise three sheets of glass and in which one of the air cavities can be replaced by a cavity filled with a gas such as krypton. These glazing assemblies have markedly improved insulation properties, but their structure and mechanical behavior are such that it is not easy for them to be used, in particular, in arrangements of the structural glazing type.
The aim of the invention is to produce an insulating glazing assembly provided with a peripheral plastic frame which obviates the various drawbacks mentioned above.